1. Field of the Invention
The present invention relates to a lock mechanism for the clutch of a reel base. This lock mechanism is designed in such a way that in a case where the clutch torque of a reel base having a clutch function is used in a recording/reproducing mode as well as a fast forward mode, the winding torque in the fast forward mode does not become smaller when the clutch torque is suppressed low by using a single clutch mechanism in order to improve the performance of the winding torque in the recording/reproducing mode, and the torque in the recording/reproduction mode does not get higher when the fast forward torque is set as high as possible.
2. Description of the Related Art
Conventionally, the clutch torque of a reel base equipped with a clutch function was used in a recording/reproducing mode as well as a fast forward mode, or a separate clutch mechanism was provided in addition to the clutch function of the reel base so that the clutch of the reel base was used in the recording/reproducing mode while the additional clutch was used in the fast forward mode and rewinding mode.
In a case where the clutch torque of a reel base equipped with a clutch function is used in a recording/reproducing mode as well as a fast forward mode, if the clutch torque is suppressed low in order to improve the performance of the winding torque in the recording/reproduction mode, the winding torque in the fast forward mode becomes smaller too. This makes tape winding incomplete. Therefore, the clutch torque cannot be decreased.
It is desirable to set the fast forward torque as high as possible. When the fast forward torque is set high, the torque in the recording/reproducing mode gets high too, which is not desirable. The prior art could not therefore provide the optimal torques for both cases.
As a solution to this shortcoming, a separate clutch mechanism may be provided in addition to the clutch of the reel base so that the torque in the recording/reproducing mode and the torque in the fast forward mode are acquired from the respective clutch mechanisms, as mentioned above. This structure is however complicated, which stands in the way of making the lock mechanism smaller and reducing its cost.